Air induction system for internal-combustion engine

ABSTRACT

The present invention provides a compact air induction system for an internal-combustion engine in which an air inlet section, a collection section and the intake port section for a plurality of cylinders of the internal-combustion engine are formed adjacent to each other and connected directly or through a partition wall. A control unit for controlling the engine is mounted in the passage at the downstream of the air inlet section.

This is a continuation of application Ser. No. 08/729,617, filed Oct.11, 1996, now U.S. Pat. No. 5,704,326, which is a continuation ofapplication Ser. No. 08/554,925 filed Nov. 9, 1995, which is acontinuation of application Ser. No. 08/332,805, filed Nov. 2, 1994.

BACKGROUND OF THE INVENTION

The present invention relates to an air induction system which suppliesair and fuel to the combustion chambers of an internal-combustionengine.

In such air induction systems, the size, shape and configuration of theair intake passage determines not only the efficiency with which intakeair flows to the combustion chambers of the engine, but also theresonance frequency of the system. The latter parameter is important inparticular when the engine is designed for resonance supercharging, inwhich case it is advantageous to provide an arrangement for modifyingthe resonance frequency of the system to adapt it to the operating speedof the engine. It is also important to make such air induction systemsas simple and compact as possible, so as to reduce the space requiredfor mounting, permitting greater latitude in the design of theautomobile engine compartment

In a prior-art as disclosed in Japanese Patent-Laid Open No. Hei4-175,465, the air induction system is compactly formed as a unit, witha collector section and a separate intake section. However, an injectionvalve, a throttle, an intake air flow sensor and an air inlet sectionare separately assembled. This arrangement is inferior with regard toassembly and mounting efficiency because the injection valve, thethrottle, the intake air flow detector, and the air inlet section areassembled separately.

It is an object of the present invention to provide an air inductionsystem for an internal-combustion engine in which an air inlet section,a collector section,and the engine intake ports, etc. are installed incompact form, for the purpose of decreasing the height of the engine toenable slanting a hood of a motor vehicle, thereby improving aerodynamiccharacteristics and fuel economy of the motor vehicle.

SUMMARY OF THE INVENTION

In the air induction system according to the invention air that hasentered at an air inlet flows through an intake air flow sensor and athrottle, into a separate passage section. From there, it flows througha collector section, into an intake port section which has separateintake ports corresponding to each cylinder, and thence into the enginecombustion chambers.

In order to achieve a compact design, the passage section, the collectorsection and the intake port section are arranged adjacent to each otherand connected directly or through a partition wall. Also a control unitfor controlling the engine is mounted in the passage downstream of theair inlet section.

According to the present invention, the whole air induction systemcomposed of the air inlet section, the intake ports, etc. is builtcompactly to thereby enable effective utilization of the interior of theengine compartment.

Because passages are formed by utilizing the partition walls foradjacently assembling the above-described parts, it is possible to makethe air induction system compact, without requiring excess space.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a transverse sectional view of an air induction systemaccording to the invention, installed in a V-type engine;

FIG. 2 is a longitudinal sectional view of the air induction system ofFIG. 1, viewed along line II--II;

FIGS. 3 and 4 are sectional views showing the air flow in a portion ofthe air induction system;

FIG. 5 and 6 are explanatory views of an intake port assembly;

FIGS. 7 and 8 are explanatory views of an air stream in the intake port;

FIGS. 9 and 10 illustrate the principle of resonance in the intake port;

FIG. 11 shows the arrangement of a swirl passage;

FIG. 12 shows the swirl valve;

FIG. 13 shows the flow dividing valve section;

FIG. 14 shows the construction of the flow dividing valve shaft couplersection;

FIG. 15 is a longitudinal sectional view showing the arrangement of anintake port body;

FIG. 16 shows a transverse section of the intake port body of FIG. 15,taken along the lines XVI--XVI;

FIG. 17 is a longitudinal sectional view showing another embodiment ofthe intake port body according to the invention;

FIG. 18 is a horizontal longitudinal sectional view of still anotherembodiment of the intake port body;

FIG. 19 is a transverse sectional view of the embodiment of FIG. 18;

FIGS. 20 and 21 show the arrangement of a fuel line, and a coolant line,respectively;

FIG. 22 shows another embodiment of the intake port body according tothe invention.

FIG. 23 is a view showing the arrangement of an EGR line;

FIG. 24 is a view showing the constitution of another embodiment of theEGR line;

FIGS. 25 and 26 show alternative arrangements for mounting a controlunit in the air induction system according to the invention; and

FIGS. 27-29 show an arrangement for electric power supply in an airinduction system according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The air induction system of the invention is arranged with an air inletsection 7, 8, a collection section 9 and an intake port section 10adjacent to each other and separated by partition walls 13.

FIG. 1 shows a first embodiment of an air induction assembly accordingto the present invention mounted in a V-type engine, with two cylinderbanks 1, 2 set at an angle to each other, right and left. This V-typeengine generally has 6, 8 or 12 cylinders, to any of which the presentinvention is applicable. In the V-type engine, a space is formed betweenthe right and left banks 1 and 2 in which the air induction system (or apart of it) is mounted. The air induction system, therefore, must bemade compact.

FIG. 1 is a transverse sectional view from the end of the engine showingthe banks 1 and 2. FIG. 2 is a longitudinal partial sectional view ofthe air induction assembly in FIG. 1. As can best be seen in FIG. 1, theair induction system according to the invention includes three principalsections or chambers, which are arranged adjacent to each otherseparated by a common wall. These include an air inlet section 7, 8, acollector section 9 and an intake port section 10. The air that hasentered an air cleaner (not shown) passes through an intake passage 4 toan air flow sensor 5, (such as a hot-wire type, moving vane type, orsensing pressure type), and then through a throttle 6 for controllingthe quantity of intake air being supplied into the engine. The throttle6 may be driven either mechanically or electrically by a motor.

The air that has passed through the throttle 6 flows through a connectorsection 7 which provides a transition from the generally circular crosssection of the throttle 6 to a passage section 8 (which has a generallyrectangular cross section), into a collector section 9 and then tointake port section 10 where it is distributed to intake ports for eachcylinder of the engine. A collector body 108 includes the air inletsection 7, and the collector section 9, and an intake port body 110includes the intake port section 10. Thereafter the air flows throughintake ports 3 into combustion chambers 12 of the engine.

In the above-described arrangement, the passage section 8, the collectorsection 9 and the intake port section 10 are situated adjacent to eachother, separated by common partition walls, and are connected directlyor through the partition walls in order to provide a compact intakesystem. The order of these three components is not specified. Asdescribed hereinafter, an electronic control unit for controlling theengine may be mounted on the partition wall 11 located between thepassage section 8 and the collector section 9 with space and coolingeffects taken into consideration. The control unit 13, therefore iscooled by intake air.

An injection valve 14 is arranged in the intake port 3 of each cylinder,as well as an air passage 15 for causing a swirl of air within thecombustion chamber 12. (This air passage 15 is unnecessary, when theformation of a swirl is not required.) In the body of the intake portsection 10 there are provided flow dividing valves 17 for controllingthe air flow into the intake port section 10 and the air passage 15 ofeach cylinder to produce the swirling motion. The flow dividing valve 17is supported on a shaft 18 and coupled to a driving device 20 by acoupler 19 installed on one end of the shaft 18. (In the presentembodiment, a butterfly valve is shown as an example of the flowdividing valve 17, but the same effect can be achieved by the use of aslide valve or other type of valve. Furthermore, the driving device 20may be an electric motor or a diaphragm making use of a pressuredifference.) As described in greater detail hereinafter, in thecollector section 9, a control valve 21 controls an air column resonancepoint in order to improve engine intake efficiency. (In the presentembodiment, a butterfly valve is shown as an example of the controlvalve 21 controlling the air column resonance point, and an actuator 16drives the control valve 21, but the same effect is feasible by the useof a slide valve and so forth.)

In the embodiment of FIG. 1, rectifiers 22, which may be made of eithermetal or a resin, are provided between the passage section 8 and thecollector section 9 where the intake passage turns, for the purpose ofdirecting the intake air flow. (FIGS. 3 and 4) In the bent section ofthe intake air flow there occurs an exfoliated air flow portion 23 asshown in FIG. 3. The rectifiers 22 provided in the passage as shown inFIG. 4, conduct the air flow around the turn, thus decreasing the amountof turbulence or the exfoliation, reducing intake air resistance likelyto be caused by the exfoliation, and accordingly preventing a reductionin power of the engine. The presence of the rectifiers 22, however, isnot essential for proper operation of the invention.

The collector body 108 and the intake port body 110, referred to above,are fastened by fastening means 24, as shown in FIGS. 5 and 6. Thecollector body 108 constructed as shown in FIG. 5 is formed with flatsurfaces and therefore is disadvantageous in the respect of strength inrelation to an external force. On the other hand, the collector body 108of the present invention constructed as shown in FIG. 6 has athree-dimensional construction which is significantly stronger.

Next a further feature of the invention will be explained by referringto FIGS. 7 and 8, in which an arrow indicates the stream of air flowingin the passage section 8 or the collector section 9. A projectionexplained in FIG. 6 is present in the passage section 8 or collectorsection 9 which may cause turbulence 26 of the air stream in thevicinity of the projecting portion 25 as shown in FIG. 7. In FIG. 8,which shows the present invention, however, a projection portion 25Agradually changes shape, and there occurs no turbulence. This preventsthe intake air resistance from increasing in this area.

The principle of resonance of the air column in the air induction systemaccording to the invention is illustrated in FIGS. 9 and 10, in which anair intake system is shown as divided between portions for each cylinderbank of a V-type engine by means of a partition wall 107, which includesa control valve 21 for controlling the resonance point of the aircolumn. As shown in FIG. 9, with the control valve 21 closed, thethrottle 6, the passage section 8, the collector section 9 and theintake port section 10 form one passage and therefore the intake passagerelated to supercharging becomes quite long, thus resulting in adecreased resonance frequency and gaining a resonance effect at a lowengine speed. On the other hand, as shown in FIG. 10, when the controlvalve 21 is open, the intake system extends to the open section of thecontrol valve 21. Therefore, because the resonance section is short,resonance supercharging is done at a high speed. The length of theresonance intake port can be changed as described above by operatingcontrol valve 21, thereby enabling the supercharging in a wide range ofengine speeds. The provision of the control valve 21 as part of thepartition wall 107 has become feasible because it is unnecessary toprovide a special intake passage, and it has thus become possible toconstitute the air induction system compactly.

Next, a mechanism for creating the swirl within the combustion chamber12 of the engine will be explained by referring to FIG. 11. The intakeair drawn into the combustion chamber 12 passes through the flowdividing valve 17 (see also, FIG. 2), the intake port section 10, andintake valves 27, being drawing into the combustion chamber 12. At thistime, the ratio of the intake air which flows through the intake portsection 10 and the air passage 15 can be changed by opening and closingthe flow dividing valve 17. When the flow dividing valve 17 is closed, alarge part of the intake air passes through the air passage 15. However,the intake air stream, having a directional property as indicated by anarrow in the drawing, produces a swirl 28 in the combustion chamber 12.In such a system for imparting the swirl motion in the combustionchamber 12 by using the deflected stream of intake air in the intakeport section 10, the flow dividing valve 17 partly having a cutout 29 asshown in FIG. 12 may be used. Furthermore, in the air induction systemhaving two air passages 15 in the intake port section of the enginecorresponding to two intake valves 27, a similar effect can be obtainedby the use of the flow dividing valve 17 designed to close the airpassage 15. In the V-type engine, the intake port section 10 is situatedin an area between the two cylinder banks and the flow dividing valve 17is also a located there. Furthermore, the plurality of the flow dividingvalves 17, as shown in FIG. 13, for all cylinders are supported by theshaft 18 (see FIG. 2).

Also as described above, the valve may be the flow dividing valve 17having the cutout 29 in a part thereof. It should be noted, however,that in the case of the system having two air passages 15 in the intakeport section corresponding to two intake valves 27, a similar effect maybe achieved by the use of two swirl control valves, one in each airpassage 15, instead of the flow dividing valve 17.

In the intake system in which the flow dividing valve 17 of all thecylinders are supported on shaft 18 alone, since the intake port body110 and the shaft 18, which are likely to have different thermalexpansion coefficients, are formed in a unitary construction as shown inFIG. 13, it is possible that the flow dividing valve 17 will fail tooperate smoothly due to temperature changes, if the axial movement ofthe shaft 18 is restricted. As shown in FIG. 14, in order to alleviatethis problem, the coupler 19 which connects the shaft 18 with thedriving device 20 is provided with a slit 19A in which a fixing pin 19Bfixed on the shaft 18 is fitted to allow the axial movement of the shaft18 to transmit only a rotary motion from the driving device 20, therebyenabling the absorption, by the axial movement of the shaft 18, of adifference in the axial thermal expansion or contraction of the intakeport body 110 and the shaft 18 caused by temperature changes. The flowdividing valve 17, therefore, can always operate smoothly. It should benoted that the arrangement of the coupler 19 shown in FIG. 14 can berealized also by such a constitution that a slit is provided in theshaft 18 and the fixing pin 19B is fixed in the coupler 19.

FIGS. 15 and 16 show additional construction details of an embodiment ofthe air induction system according to the invention. FIG. 15 is alongitudinal sectional view which shows intake air drawn in as indicatedby the arrow. FIG. 16 is a transverse sectional view showing the presentembodiment taken along line a--a of FIG. 15. The passage section 8 andthe collector section 9 are divided longitudinally by partition walls111 and 112 (FIG. 16) respectively to separate the passage section 8 andthe collection section 9 for each bank of the engine, for the purpose ofresonance supercharging as previously described. In the presentembodiment, the collector body 108, and the passage section body 106both have an E-shaped sectional form and are formed by superpositioning.This type of construction provides additional strength with respect toan external force because of the partition walls 111 and 112 of ribbedconstruction, and because of the effect of superpositioning. Thisarrangement is also advantageous in manufacturing and cost because ofits relatively simple configuration. If no resonance supercharging isadopted, the passage section body 106 and the collector body 108 neednot be of an E-shaped sectional form, and may be of a channel-typesection or a box-type section.

FIG. 17 shows another embodiment of the invention, in which thecollector body 108 is superposed in three stages. In this arrangement,the intake air stream from the throttle 6 to the intake port section 10is as indicated by the arrow in the drawing. For a given fixed length ofthe intake passage, the longitudinal mounting space of the air inductionsystem viewed in the longitudinal direction of the engine can bedecreased. In this drawing, the air induction system has the threestages of collector body superposed, but the number of stages is notlimited.

Still a further embodiment of the invention shown in FIGS. 18 and 19provides an alternative arrangement of the passage section 8 and thecollector section 9. The intake air that has passed through the throttle6 flows through the passage section 8 and collection section 9, whichlie adjacent each other in a horizontal arrangement, and then into theintake port section 10. A partition wall 109 is provided with thecontrol valve 21 controlling the air column resonance point. In thisembodiment, because the passage section 8 and the collector section 9are arranged in the horizontal direction with respect to the engine, itis possible to decrease the required space in the height direction ofthe engine. It is to be noted that where no resonance supercharging isadopted, there is no necessity to separate the collector as in thepresent embodiment and the collector may be of one box-typeconstitution. FIG. 19 shows the section b--b of FIG. 18; the passagesection 8 and the collection section 9 arranged horizontally areseparated by the partition wall 109 by each cylinder bank relative tothe engine. Here, the number of rows of the passage section 8 and thecollection section 9 is not limited.

FIG. 20 shows a transverse sectional view of the injection valve 14section, which is installed within the intake port body 110. Theinjection valve 14 receives the fuel being supplied through a fuel line30 arranged in the intake port body 110. Within the intake port body 110is provided an intake air line 31 for improving fuel atomization at thetime of fuel supply from the injection valve 14 to the engine. The airsupply form the intake air line 31 to the injection valve 14 is effectedthrough a small hole 31A. The present embodiment, as described above,requires no separate feed lines like those in conventional intakesystems, for supplying the fuel and air to the injection valve 14, andtherefore is effective to decrease mounting space and cost. The presentembodiment is feasible as a matter of course even in the constitutionwithout the intake air line 31, that is, in the system which will notimprove fuel atomization by the air.

FIG. 21 is a sectional view showing the injection valve 14 like FIG. 20.The injection valve 14 is supplied with the fuel from the fuel line 30installed within the intake port body 110. In the vicinity of the fuelline 30 in the intake line body is provided a cooling fluid passage 32.The cooling fluid flowing in the cooling fluid passage 32 flows throughin the engine. Flowing the cooling fluid through the cooling fluidpassage 32 cools the fuel line 30, and therefore, it is possible toprotect the fuel line 30 from heat from the engine, and accordingly toprevent vapor lock in the fuel system.

FIG. 22 is a sectional side view of a variation of the embodiment ofFIG. 2. (Members performing the same function are designated by the samereference numerals as those used in FIG. 2.) In this arrangement, theair from the air cleaner (not shown) flows through the passage 4, pastthe intake air flow sensor 5, and through the throttle 6, which controlsthe intake air flow to the engine. The air that has passed the throttle6 flows through the passage section 8 and the collector section 9, intothe intake port section 10 corresponding to each cylinder. Thereafter,the air flows through the intake ports 3 of the engine into thecombustion chamber 12 (FIG. 1). In this embodiment, the intake port body110 is formed of metal, and the collector body 108 is formed of resin.The intake port body 110 formed of metal is effective to restrainvibration of each bank inherent to the V-type engine, whereas thecollector body 108 formed of resin, which has a high freedom of molding,and can realize an intake port of nearly ideal configuration. Moreover,because the wall thickness of, collector body 108 can be decreased, itis possible to reduce the required mounting space and weight.Furthermore, a resin molding, generally has a smoother surface than ametal molding, and will not increase the intake air pressure in theintake port section 110 when used in the intake port, and accordingly,has an effect to improve the intake efficiency. It should be noted that,in the present embodiment also, a part or all of the componentsexplained in the embodiment referred to in FIG. 2 are applicable.

FIG. 23 is a sectional side view of an embodiment of the invention inwhich an EGR (exhaust gas recirculation) outlet port 33 opening into theair inlet section 7 is located at the downstream side of the intake airflow path of the throttle 6 of the collector body 108. The provision ofthe outlet port 33 in the position shown in the drawing allows effectivemixing of the intake air and the EGR gas, thereby insuring gooddistribution of the EGR gas to each cylinder of the engine.

FIG. 24 shows a cross section of the injection valve 14 in the intakeport body 110, in FIG. 23. (Members having the same function aredesignated by the same reference numerals in FIGS. 20 and 21.) Withinthe intake port body 110 is provided an EGR line 34, which is connectedby a passage 34A to the intake port section 10. When the arrangementdescribed above is used, there is no necessity to provide any additionalpipe because the EGR line 34 is formed integral to the intake port body110, and good air distribution to each cylinder is insured. Also sincethe outlet port 33 is located downstream of the injection valve 14, theinjection valve 14 is unlikely to get stained.

FIG. 25 is a longitudinal section for the present invention, which showsa possible arrangement of an electronic control unit in the air passage.The air inlet section 7 and the passage section 8 in this case are thesame as that explained in FIG. 2 and other figures. The control unit 13is provided within the passage section 8, thereby eliminating the needfor a special mounting space. It is cooled by the intake air drawn inthrough the throttle 6. Furthermore, since the passage section 8 inwhich the control unit 13 is mounted on the partition wall 11 isconnected to the intake port section 10 through the collector section 9located downstream, there is no danger that the control unit 13 will getstained with blow-by fumes from the engine. FIG. 26 shows anotherembodiment in which the control unit 13 is mounted on the upper wallsurface of the collector body 108. In this case also the same effect asthat explained in FIG. 25 is obtained and will not be adversely affectedif the wall surface is on curved so long as it is the inner wall surfaceof the collector body 108.

A further feature of the air induction system according to the inventionwill be explained by referring to FIG. 27. FIG. 27 shows the sectionC--C of FIG. 26, in which the location of the section C--C is set inthis position for the above-described reason, but is not restricted. Thecollector body 108 includes wires 35, by which the electric current isfed to each part.

FIG. 28 shows a variation of FIG. 27, wherein the wires 36 have a squarecross section. Of course, the cross sectional configuration of the wires36 is not limited. Since the aforementioned arrangement can save thewire's space and moreover the wire itself requires no insulatingcovering, the air induction system has such an advantage as space savingand cost reduction.

FIG. 29 shows a section of the end of the wires 35 or 36 arranged insideof the collector body 108. A connecting terminal 37 is provided at theend of the wires 35 or 36,and a connector 108A is molded integral withthe collector body 108, to thereby enable connection of the wires forelectric power supply to or electric power reception by, each part. Thisarrangement eliminates the need for separately preparing the connectormentioned above, thereby enabling space saving.

According to the present invention, the air induction system can be madecompact while improving the intake performance. Thus, the engine can becompactly constituted, to thereby impart improved freedom of design toan automobile, and consequently to enable energy saving and costreduction, thus obtaining a great advantage as the automobile.

Although the invention has been described and illustrated in detail, itis to be clearly understood that the same is by way of illustration andexample, and is not to be taken by way of limitation. The spirit andscope of the present invention are to be limited only by the terms ofthe appended claims.

What is claimed is:
 1. An air collector for guiding a flow of air froman air inlet to an intake port body of an internal combustion engine,comprising:a first air flow body connected with said air inlet and afirst side of intake ports of said intake port body, with a throttlevalve interposed therein; a second air flow body connected with said airinlet and a second side of intake ports of said intake port body, withsaid throttle valve interposed therein; a shared wall disposed betweenand separating said first and second air flow bodies; a hole disposed insaid shared wall at a point separated from said air inlet; and a controlvalve disposed in said hole for controlling a resonance effect; whereinsaid first and second air flow bodies are adapted to be mounted on saidintake port body.
 2. An air collector according to claim 1, wherein saidfirst and second air flow bodies are disposed horizontally to saidengine.
 3. An air collector according to claim 2, wherein said first andsecond air flow body have refrain passages in which a direction of saidflow of air is opposite to a direction in said first and second air flowbodies.
 4. An air collector according to claim 3, wherein said first andsecond air flow bodies and said refrain passages are divided by walls.5. An air collector according to claim 1, wherein said engine has twobanks having cylinders which are arranged in a V shape, and said firstand second air flow bodies are disposed on said banks of said engine. 6.An air collector according to claim 1, further comprising:a control unitmounted on an interior surface of a wall of said collector, forcontrolling said engine.
 7. An air collector according to claim 1,further comprising:an electric wire for supplying electricity to a fuelsupply device, said wire being arranged on an interior surface of a wallof said collector.
 8. An air collector according to claim 7, whereinsaid electric wire is embedded in a wall of said collector.
 9. An aircollector according to claim 7, wherein said collector is made of aresin material having fibers arranged longitudinally adjacent to saidcollector.
 10. An air intake system for guiding a flow of air to anintake port body of an internal combustion engine, comprising:an airinlet; an air flow body which is adapted to be mounted on said intakeport body, and has first and second air passages separated by a sharedwall therein, each of said air passages connecting said air inlet, via athrottle valve, to a different group of intake ports of said intake portbody; a hole in said shared wall, situated at a point separated fromsaid air inlet; and a control valve disposed in said opening, foropening and closing said hole, regulating a resonance effect in said airflow body.